Electrical discharge device



Jan. 16,1934. c, s I 1,943,847

ELECTRICAL DI SCHARGE DEVICE Filed 001?. 23, 1930 HBRLfiS SPA 61'" INVENTOR ATTORNEY I cordance with vapor is introduced into the lamp proper the lamp may become @atenteol Jan. H6, 1934 ilflldimil nsnornroan prsonanos nsvros Charles Spaeth, Flushing,

Ne-Arga Corporation, .lersey poratlon of New llorls N. Y., assignor to City, N. li., a cor Application (llctoher 23, 193%. Serial No. 496L646 r. claims. (or. lio lzdi This invention relates to electric discharge lamps, and more particularly to lamps oi the type described in my copending application, filed of even date herewith, in which the color spec trum radiated by the lamp is controlled by means of a reservoir of mercury from which mercury at a predetermined rate.

in accordance with the disclosure forming part of said pending application, the vaporization of the mercury is controlled by means of an auxiliary electrode immersed therein, the current flow from the positive side of the line (connected with the anode) being controlled in turn. by a variable resistance. In operating lamps of this type I have found that under certain conditions unstab instance, that where to sudden variations, it becomes difficult to control the color of the lamp. In case there is a sudden increase in the line voltage, more than the required quantity of mercury vapor is introduced into the lamp proper, causing it to turn bluish. Furthermore, owing to the presence of more than the required mercury vapor in the lamp, the latter draws a great deal of current and may cause the burning out of resistances. In case there is a suddentdrop in line voltage,

less than the required quantity of mercury vaporis produced, thelamp turns reddish (assuming that it contains neon), its internal resistance increases and the lamp may even go out.

In order to obviate these drawbacks, in acthe present invention, the auxby means of which the mercury heated, is connected through a iliary electrode, or the like is of the positive side of the line. When so connected the lamp burns steadily and emits a predetermined spectrum without regardto the usual line voltage variations.

The invention is more clearly set forth in the following detailed description and the drawin in which Figs. 1, 2, 3, 4 and 5 illustrate schematically five embodiments of the Throughout the drawing, corresponding elements bear the same reference numerals.

Referring now to Fig. 1, 1 is a glass envelope or tube containing the usual fllling'of rare or mo'natomic gas, such as neon, an anode 2 and analkallne metal cathode 3. A reservoir 4 conof mercury 5 is connected with The anode 2' is connected through a fixed resistance 6 with the positive side of the line (supplying say, 220 v. D. C.) and the oathle. 1 have found, for l the line voltage is subject invention.

ode is connected with thenegative side of the line. An auxiliary electrode 3' immersed in the pool of mercury 5 is connected through a vari= able resistance 8 with the negative or cathode side of the tube.

Owing to the shortness of the path between the auxiliary electrode 7, which is now negative, and the anode, a discharge between the two can easily be produced, and once the lamp is opcrating in the manner described in my co-pending application, it willradiate the predetermined spectrum which remains constant even where the line voltage varies as much as plus or minus 30 v.; that is to say, with a lamp designed to operate on 220 v. D. C., its characteristics will remain constant at from 190 v. to 250 v.

In the arrangement shown in'Fig. 2, the auxlliary electrode 7 coarse filament of tungsten wire 9 with the positive side. of the tube. In the normal operation of the device, the tungsten filamentQ glows at a dull red color and will aid in the vaporization of the mercury. I have found that lamps constructed in accordance with is connected through a rather this embodiment start very easily, even'where the 'passagewaybetween the reservoir and the main envelope is restricted or the-arrangement for any desired operating characteristics.

A modification of thelast mentioned arrangement is shown in voir 4 with the anode chamber.

In the arrangement shown in Fig. 4, the aux iliary electrode '7 is connected with the negative side of the tube and the variable resistance 8, also provided in the negative connection of the tube, connects with one end of the tungsten filament 9.

Referring now to Fig. '5, we have the same type of lamp as above described. However, heating current for the auxiliary electrode '7 and the tungsten filament 9 is supplied from a sourceof 110 v. A. 0. through the usual variable resistance 8 and a transformer 10. The auxiliary electrodes and tungsten filaments of a number of other tubes (all like the one shown), indicated at.9 and 9 are connected in parallel withthe auxiliary electrodes of tube 1 and are thus supplied with heating current from a common source.

Obviously, other modifications a d embodi- Fig. 3 in which the tungsten filament 9 is connected with the anode side of the tube through the tubing which links the reservariable resistance with the negative instead ments may be practiced within the spirit of the present invention.

What is claimed is:

1. In an electric discharge device, a light transmitting envelope, a rare gas filling in said envelope, an anode and a cathode within =aid envelope, a reservoir containing mercury connected with said envelope near said anode, an auxiliary electrode immersed in said mercury, a filament within said reservoir and connected at one end with said auxiliary electrode, a source of current, a connection from the positive side of said source to said anode, a fixed resistance in said connection, a connection from the other side of said filament with said connection at a point between the anode and said resistance, and a variaelectrode and the negative side of said source.

2. In an electrical discharge device, an envelope, a filling of neon gas within the envelope, said filling being adapted when ionized to give off light, an anode and a cathode, the cathode comprising an alkaline metal for passing a discharge through said gas, a reservoir, said reservoir containing mercury, the mercury being adapted to give 011 vapor capable of modifying the color value of said, rare gas, auxiliary means comprising'a variable resistance connected in series with the mercury and the negative side of the current supply, the mercury constituting a cathode and establishing a flow of current from said anode to the mercury contained in said reservoir.

CHARLES SPAETH. 

